The present invention relates generally to the field of vented battery caps, and more particularly to a multiple plug vented battery cap which reduces the loss of battery electrolyte during battery use and/or minimizes the expulsion of gases from the battery into the atmosphere.
It is well known that a suitable battery vent plug must provide for the expulsion of gases which build up during the chemical reactions which take place during the charging and discharging of a battery, while effectively preventing the leakage or evaporation of substantial quantities of the battery electrolyte. To this end, battery vent plugs are normally designed with gaseous evacuation means for venting the gases produced within the battery to the atmosphere, while providing electrolyte retention means within the battery vent plug for retaining and returning to the battery as much of the electrolyte as is practically feasible. This retention of battery electrolyte is normally accomplished through the use of various baffles and/or gabled floors in the battery vent cap which tend to funnel the battery electrolyte which escapes into the battery vent plug back into the cells of the battery.
In the interest of safety, it is also desirable that the battery vent plug be designed to minimize the chance that a spark occuring in the vicinity of the battery could ignite escaping battery gases, thereby resulting in a possible explosion of the battery vent cap away from the battery container, or even the explosion of the battery itself.
Conventional maintenance requiring batteries are generally provided with a plurality of removable vent caps, through which fluid may be added to the cells as required, each of which is configured to satisfy one or more of the above requirements. Moreover, in recent battery designs, it has become common to mate a plurality of cell vent caps, generally three, into a single "gang" type vent, to provide additional area over the cells of the battery for gathering the vapors that are produced as the battery is charged or discharged, and to condense them for re-entry into the battery. This serves to reduce the amount of maintenance required on the battery to maintain the required fluid level in each cell.
Recent technology has produced what is sometimes referred to as the maintenance free battery, having essentially sealed tops which do not permit the addition of fluid to the individual cells. The maintenance free battery uses a very large condensing area above the plurality of cells, and a battery case having vent frits which are spaced apart from the cells opposite the respective positive and negative terminal posts to permit the escape of explosive gases to the atmosphere, thus preventing battery explosions.
It is the purpose of the present invention to provide a conventional maintenance requiring battery with a venting cap structure which is specifically adapted to substantially reduce battery maintenance, yet which is fully compatable with conventional maintenance requiring batteries, permitting convenient access to the cells of the battery should servicing of the battery ever become necessary.